At the beginning of the film, the cameras are all positioned above eye level and mounted with wide-angle lenses to give the appearance of greater distance between the subjects. As the film progresses the cameras slip down to eye level. By the end of the film, nearly all of it is shot below eye level, in close-up and with telephoto lenses to increase the encroaching sense of claustrophobia.
As shooting of the film went on, director Sidney Lumet gradually changed to lenses of longer focal lengths, so that the backgrounds seemed to close in on the characters, creating a greater feeling of claustrophobia.
For many years, only the first half of the kinescope of the TV version of "Twelve Angry Men" broadcast live on Sept. 20, 1954 (Studio One in Hollywood: Twelve Angry Men) was thought to survive, and had been in the possession of the Museum of Television and Radio since 1976. In 2003 a complete 16mm kinescope was discovered in the collection of Samuel Leibowitz (former defense attorney and judge) and was also acquired by the museum.
Most of the hard-working (relatively inexperienced) crew were longshoremen. Because there wasn't enough movie work to feed them all year, they'd have two union cards: their Local 52 cards and their ILA cards.
Only two jurors are ever identified by name: #8 Mr. Davis and #9 Mr. McCardle. And all but two are identified by job or profession: #1 High School Football Coach, #2 Bank Teller, #3 Owns Messenger Service, #4 Stock Broker, #6 Painter, #7 Salesman, #8 Architect, #10 Garage Owner, #11 Watch Maker, and #12 Advertising Exec.
Sidney Lumet had the actors all stay in the same room for hours on end and do their lines over and over without taping them. This was to give them a real taste of what it would be like to be cooped up in a room with the same people.
Because of the demands of the film's low budget, if the lighting was set up for a shot that took place from one particular angle, all the shots from that same angle had to be filmed then and there. This meant that different sides of the same conversation were sometimes shot several weeks apart.
Henry Fonda immediately complained to Sidney Lumet about the cheap backdrops outside the jury room windows when he walked on set. "They look like shit. Hitch had great backdrops, you could walk right in them," said Fonda, referring to the previous film he made with Alfred Hitchcock, The Wrong Man. Lumet assured him that the director of photography Boris Kaufman had a plan to make them work.
The ethnic background of the teen-aged suspect in the film was deliberately left unstated. For the purposes of the film, the important facts were that he was NOT Caucasian and that prejudice (or lack of it) from some jurors would be a major part of the deliberations process.
When John Calley was running United Artists pictures between 1993 and 1996, he gave an interview to "The New Yorker" where he discussed UA's continuing rights to the project, and said he had looked into a possible remake that would have starred Michelle Pfeiffer and been set around the 1992 Los Angeles riots in the aftermath of the Rodney King trial verdicts.